The present invention relates to a solid-state image pickup apparatus, and more particularly to a technique of increasing the dynamic range of a solid-state image pickup apparatus of amplification type.
One of the important features of solid-state image pickup apparatuses is dynamic range. The dynamic range is determined by the signal charge that can be accumulated in each unit cell. The smaller the unit cell, the smaller the capacitance for accumulating the signal charge, and the smaller the saturated signal charge. If the saturated signal charge is small, it will be impossible to increase the dynamic range.
No sufficient measures are taken to increase the dynamic range, in conventional solid-state image pickup apparatuses of amplification type. Consequently, the conventional solid-state pickup apparatuses of this type cannot have high performance.